When to use laser cutting for a new part

When to use laser cutting, in four tests

A new part arrives as a STEP file, a quantity and a date. The route decision made in the first hour usually survives to the end of the programme, and it is made on four things: thickness, feature type, the order in which features must exist, and annual volume. When to use laser cutting is answered by those four, in that order, and the machine is the last question rather than the first.

The short version. Laser cutting is the right route for a flat part from 0.8 mm to 20 mm where the geometry is still moving, the volume does not justify a die, or a feature has to be cut before the part is formed. It is the wrong route for a stable blank at high volume, for anything with a formed feature in the profile, and for plate beyond the machine's ceiling.

The rest of this page is the arithmetic behind that rule, because the arithmetic is what a buyer has to defend.

Test one: thickness and material

Thickness sets the process before anything else does. At Ganesh the 12 kW fibre laser cuts to 20 mm plate, and the practical cost curve turns upward well before that. Cut speed on mild steel falls from metres per minute at 2 mm to a fraction of a metre per minute at 16 mm, while pierce time grows from a fraction of a second to several seconds. A 20 mm contour is a legitimate laser job; a 20 mm part with 60 holes in it usually is not.

Material changes the answer again. CRCA and mild steel are the easy case. Stainless steel cuts cleanly but the edge oxidises if nitrogen is not used, and the oxide has to be removed before welding. Aluminium conducts heat away from the cut and needs more power and a different assist strategy. Copper and brass reflect most of a 1,064 nm beam until the surface melts, which is why they are cut at the thin end of the range and priced accordingly.

Below 0.8 mm the handling problem overtakes the cutting problem: the sheet distorts, parts lift, and the labour per part rises faster than the material cost falls. That is a stamping or a fine-blanking job, not a laser job.

Test two: what the edge has to do

A laser edge is a thermal cut. ISO 9013:2017 classifies those cuts and sets quality tolerances for laser cuts from 0.5 mm to 32 mm, and it deliberately does not cover flatness, which is a material and handling question rather than a cut-quality one. What the standard gives a buyer is a vocabulary: perpendicularity, drag, dross and roughness, expressed as a class rather than as an opinion.

For most brackets and panels, a deburred laser edge is fine and the class never needs to be named. It matters in three places. A visible edge on a powder-coated panel shows every scratch from deburring, so the cut quality and the deburr method have to be agreed together. A weld prep edge needs a square face and no oxide. A hole that carries a fastener needs a diameter that stays inside tolerance through the taper.

The practical rule on holes: keep a functional hole at 1 × thickness or larger, and a non-critical hole at 0.8 × thickness. Below that, the pierce has nowhere to go, the hole tapers visibly, and a drill is the cheaper answer even on a laser part.

Test three: the order features must exist in

This is the test buyers skip, and it is the one that decides between laser and press.

A press tool forms and pierces in one stroke, so a hole that sits close to a bend is punched before the bend and then distorted by it. A laser cuts the flat blank, and the same hole is distorted by the same bend. Neither process escapes the geometry. What changes is the cost of finding out: with a laser, the first article shows the distortion before a tool exists, and the hole can be moved in the next revision for the price of a new program.

That is why a new part with an unresolved hole-to-bend question belongs on a laser first. The rule itself is geometric: keep a hole at least 2.5 × thickness plus the bend radius away from the bend line, and further if the hole is a close-tolerance feature. The full derivation is in hole-to-bend distance in sheet metal design.

The same logic applies to any feature that has to be cut before coating, before welding or before assembly. A laser puts the feature in the flat, in one setup, with no tool to modify when the position moves.

Test four: quantity against the tool

Quantity is the last test because it is the only one a buyer can change after the drawing is frozen. The comparison that matters is not laser piece price against tooled piece price, because those two numbers are not the same thing. A tooled piece price excludes the tool, the trial, the first article and the cost of a change.

The honest comparison is three lines. Tool cost divided by annual quantity, added to the tooled piece price. Laser piece price, with no tool line. And a change allowance for the first year, because a new part almost always moves once after the first build.

Two consequences follow. Below roughly a thousand parts a year, the tool line usually dominates and the laser wins even at a higher piece price. Above several thousand, the tool amortises and the press wins on piece price, provided the geometry is genuinely stable. Between the two, the decision is about risk rather than cost: a laser keeps the revision free and the first article quick, and that is often worth more than the piece price difference on a part that is still being integrated into an assembly.

What the laser route costs downstream

The cut is the first operation, not the part. A laser-cut blank still needs deburring where the edge is handled, forming on the press brake, welding if it is part of an assembly, and coating if it ships painted. Each of those steps has its own tolerance and its own inspection point, and the laser route only helps if it makes them cheaper or more repeatable.

It usually does in two places. Deburring is predictable, because a laser edge has a consistent burr on one side and can be tumbled or linished in one pass rather than chased by hand. And the flat pattern is a file rather than a tool, so a part that fails at forming can be re-cut with a corrected bend allowance in days rather than weeks.

It does not help where the cut blank needs a feature the laser cannot produce. A part that needs a louvre in the middle of a panel, or a bridge to retain a cable, is a press part with a laser blank, and the quotation should say so rather than treat the missing feature as a detail to be resolved later.

Route selection at a glance

Worked: why a 6 mm panel is pierce-bound

Take a 500 × 400 mm panel in 6 mm mild steel: a 1,800 mm outline, 48 holes at Ø8 mm, and six slots 60 × 10 mm.

Cut length is 1,800 mm for the outline, 48 × 25.13 = 1,206 mm for the holes, and 6 × 131.4 = 788 mm for the slots, which is 3,794 mm in total. At a planning speed of 2.2 m/min, or 36.7 mm/s, that is 103 seconds of cutting.

Now count the pierces: one per hole, one per slot, one for the outline, so 55. At 1.5 seconds each on 6 mm plate, that is 82 seconds. Piercing is 44% of the machine time on a part that looks, on a drawing, like a cutting job.

The design lever is therefore hole count, not cut length. Two Ø8 mm holes pass the same flow as one Ø11.3 mm hole, because 2 × 50.3 mm² is 100.5 mm² and a Ø11.3 mm hole is 100.3 mm². Consolidating 48 holes into 24 removes 24 pierces, saves 36 seconds per part, and across 500 parts that is 18,000 seconds, or 5 hours of machine time, for a change that costs nothing in material.

New parts on the 12 kW laser and the 200 T brake

New parts are quoted against the real route rather than a nominal one. Cutting runs on the 12 kW fibre laser with a 40 ft × 16 ft bed, 12,192 × 4,877 mm, supported by two 6 kW and two 3 kW machines for smaller nests. The bed size is why a 3,000 mm canopy or coach panel is a single cut part rather than two pieces welded together.

Forming is on the 200 T, 5-axis CNC press brake with a 4,450 mm bed and Delem control, to 10 mm. Welding uses three CLOOS robotic MIG cells and more than 30 manual MIG/MAG, spot and SPM stations, with fixtures designed and built in-house. Finishing runs through a 16 ft × 16 ft shot blast chamber, seven-tank pretreatment, an 18 ft × 14 ft powder booth, a wet paint line and a curing oven.

Programmes run under ISO 9001:2015 and ISO 14001:2015, with first article inspection and PPAP documentation available. Published customer programmes include Mahindra, Mahindra Powerol, Godrej & Boyce, TKE, Eros Elevators, Minda, Gunnebo and Indian Railways. The laser cutting capability page carries the machine list and the material range.

What to put on the drawing for a first quote

• Material and grade, thickness, and the mill certificate requirement if the part is structural.
• The formed drawing or the STEP file, not a flat pattern with an unexplained K-factor.
• Which dimensions are functional and which are reference, so the tolerance budget goes where it is needed.
• Hole callouts with the fit named: clearance, tapped, reamed or free.
• The edge requirement: deburred all over, deburred on visible edges only, or an ISO 9013 class.
• Finish and the masked points, if the part is coated after fabrication.
• Annual quantity and the release pattern, because 12 releases of 50 parts is a different price from one release of 600.

The laser cutting cost estimator gives a first-pass material and machine split from those inputs, and laser cutting tolerances for OEM parts covers the callouts that survive into production.

When laser cutting is the wrong route

A laser cuts a flat profile. It cannot put a louvre, a bridge, a clinch, an extruded collar or a countersink into a part, and it cannot form a rib. A part with any of those features needs a press tool, and the tool is the cost of the design rather than the cost of the volume.

It is also the wrong route for a stable blank at high annual volume. Once the geometry stops moving and the quantity is in the thousands, a blanking or progressive tool wins on piece price, and the crossover is worked in laser cutting versus stamping. We do not run a tube laser, a 5-axis laser for formed 3D parts, or wire EDM, so a part that needs any of those is outside what this plant can quote honestly.

The laser cutting and fabrication hub collects the rest of the family, including how nesting reduces sheet metal cutting cost for the material side of the same decision.